Knife sharpening device



July 31, 1934. J. WHITE 7 1,968,472

KNIFE SHARPENING DEVICE Filed Feb. 10, 1933 IN VEN TOR JOSEPH WH/ r5 BY g:

- QTTORNEY Patented. July 31, 1934 srA'rss PATET OFFEE 3 Claims.

This invention relates to sharpening devices for knives, and has for its object the provision of means for imparting a keen cutting edge to a knife, without abrasion of the material of the blade at any region thereof remote from the cutting edge.

Another object of the invention is to provide a knife sharpener in which a roll or series of rolls is maintained in juxtaposition with a roller having a peripheral groove, or series of grooves disposed transversely of the axis of the roll, with each of the series of spherical members partially entering a groove of the roll, so that a knife blade may be drawn between the sharpening element constituted by each spherical member and the coacting shoulders of the grooves of the opposed roll.

Still another object of the invention is to pro vide a device constituted of a plurality of sharpening elements assembled in the above relation, with a supporting frame which can be readily attached to a suitable support, such as a table.

Among other objects of the invention is to provide a device of the above construction which oomprises a pair of rolls each having a series of arcuate peripheral grooves separated by peripheral shoulders of greater diameter than the grooved portions of the rolls, the grooves in the rolls being disposed in opposed pairs, and to provide a series of the spherical members, one spherical member being disposed between, and having diametrically opposite portions of its periphery partially entering, the opposed grooves of a pair.

Still another object is to provide a supporting frame with such a complement of opposed rolls g5. and intervening balls and with a guide device e: tending in parallelism with the axes of the rolls, to in directing the knife blade to be sharpened into correct sharpening engagement with the series of spherical members and the edges of said shoulders, so that as a knife blade is drawn along the guide, each portion of its cutting edge will be engaged progressively with a plurality of the spherical members and the coasting roll shoulders aiong one side of a roll.

The above, and other, objects of the invention are illustrated and described fully in the accompanying drawing specification and are pointed out in the claims.

In the drawing,

Fig. 1 is a plan view of a knife sharpener in the construction of which the invention has been embodied,

Fig. 2 is a view in side elevation of the same,

Fig. 3 is a vertical, transverse section on the line 33 of Fig. 2,

Fig. 4 shows the device in end elevation,

.Fig. 5 shows a modified form of the roll element of the device, and

Fig. 6 shows a slightly modified form of the device in end elevation.

In a now-preferred embodiment of the invention, selected for illustration and description, the parts designated respectively by the reference characters 11 are spherical sharpening elements or members, preferably round balls of hardened and polished steel, disposed in a row lengthwise of a frame 12 which may be of any suitable material and shape, and which is herein shown as comprising a body portion of flat metal, having its ends 13 bent or extended upwardly and connected by a bridgepiece 14 which is intended to aid in retaining the balls in place, and also to serve as a guide, as will be described more at length.

In further pursuance of the invention, the knife sharpener is provided with one or more sharpening elements adapted to coast with the spherical elements, and of which a pair is shown, at 15 and 16 respectively, taking the form preferably of elongated rolls having their axes extended in parallelism with the series of spherical members 11, and each roll having a series of transverse depressed portions 17, each groove on the roll 15 being disposed opposite a groove on the roll 15, so that the grooves are disposed in pairs.

The rolls 15 and 16 have their axes 18 extended to form shafts journalled in suitable bearings in the upright parts 13 of the frame, and the rolls are so spaced apart that each of the spherical members 11 has diametrically opposite portions of its periphery entered within the opposed grooves of a pair.

The rolls are preferably formed with collars or shoulders 19 which may be integral therewith, and the shoulder of each collar adjacent to one of the spherical members 11 constitutes therewith a sharpening couple adapted to pinch and sharpen a knife edge as the blade is drawn along the series of spherical members and shoulders, parallel with the guide 14. I

The guide 14, shoulders 19, and grooves 1'7 constitute sockets, one for each of the spherical members, which are preferably disposed loosely in their respective sockets, so that they may be adjusted readily by hand to present fresh surfaces for action upon a knife edge, or may rotate possibly under the drawing action of the blade, although this is not to be considered as an essential feature of operation.

The rolls l5 and 16 are similarly adjustable rotatively around their axes, and to facilitate such rotative adjustment manually the rolls may have their shoulders 19 grooved, as shown in Fig. 1, or knurled or otherwise roughened in the manner illustrated in Fig. 5.

It will be noted that each roll with the adjacent coacting ball peripheries constitutes a complete sharpening device in itself, without regard to the similar sharpening device constituted by the other roll and the portions of the balls adjacent thereto, and a pair of rolls is provided rather than a single roll, merely as a matter of convenience and to afiord two available sharpening devices, which may be used alternatively to distribute the wear and increase the life of the appliance.

If only one roll is used, it will be understood that the structure of the frame could be suitably modified to prevent escape of the balls 11 on the side from which the roll is omitted, and other modifications or" structural detail may be adopted by those skilled in the art, without departing from the spirit of the invention. For example, the clamping arrangement, comprising the frame part and wing-screws 2]., may be replaced by a handle (not shown) if it be desired to utilize the appliance as a hand-carried device rather than as a table-supported sharpener, or the base 12 may be grasped by hand and the appliance so used without a handle.

The guide 14 preferably is rounded off on each side as indicated in Fig. 4 to aid in guiding the knife blade into sharpening engagement witli the sharpening elements above described.

It will be clearly understood from the above description that I have provided a sharpening appliance of sturdy, effective construction, easily kept clean, not liable to get out of order, and of a very durable character. In use it has been found that the balls and rolls coact to sharpen only the extreme edge of the blade, without abrasion of any other part thereof, particularly the heel portion of the knife, as the sharpening elements cooperate by removing particles of the material only at the cutting edge of the blade, so that plated knives can be sharpened effectively without injury or mar-ring of their finish By drawing a knife first along the elements at one side 01" the appliance and then along the elements at the other side of the appliance, each side of the edge is subjected to a uniform sharpening action, while the knife is guided by the which act as conveyors therefor, so as to prevent its dropping too far into the device, and each such drawing or" th knife is accomplished more easily than with similar appliances in which use is made only of grooved rolls, or other such app iances, in which use is made only of spherical elements.

The sharpening operation can be accomplished more rapidly and smoothly by reason of the presence of the spherical members, and more effectively by reason of the presence of the shoulders of the roll grooves, with their superior abrasive action on the edges of the knife.

As the balls act merely as a conveyor guide for the knife without any cutting action thereby, and there being a definite clearance between such balls and the grooves into which they partially extend (as will be noted from Figs. 1 and 3) gauging of the depth to which the latter enters within the grooves of the rolls is possible so that a predetermined amount of material can be shaved from the surface of the blade as the knife is pulled from heel to toe and the bevel given to the knife being sharpened can be governed by the pressure with which the knife is drawn through the device.

In Fig. 6, I have shown a slightly modified form of my device, in which the guide or bridge-piece 14 carries a stone 14 which may be used as a whet-stone to remove, from the surface of the sharpened knife, any metal particles that may have been removed from the knife blade as it was sharpened and have clung to such blade.

I claim:

1. A knife-sharpening device a rol' having an arcuate peripheral g oove disposed transversely of its length, a spherical member acting as a conveyor partially entering said groove of the roll so as to leave a clearance between said spherical member and groove, and a frame in which roll and spherical member are mounted rotatably in ambled relation, the roll having shoulders on each side of the groove adapted to constitute sharpenir. elements.

2. A inure-sharpening device comprising a roll having arcuate peripheral grooves disposed transversely of its length, a series of spherical member acting as conveyors am means for gauging the bevel to be given to the knife, each partially entering a groove of said oll so to leave a clearance between the cal members and said grooves, and a frame in which said roll and spherical members are mounts; rotatably in assembled relation, the roll having shoulders'on each side of each of the grooves adapted to constitute sharpening elements.

3. A knife-sharpening device comprising a pair of rolls having opposed arcuate peripheral grooves disposed transversely of their length, an opposed to each other in pairs, and a series of spherical members, acting as conveyors and means for gauging the bevel to be given the knife, each disposed between, partially entering, the opposed grooves of of so as to leave a clearance between the spherical members and said grooves, and a frame which said rolls and spherical members are mounted rotatably in assembled relation, said frame having a part arranged to cooperate with said rolls to form sockets in which spherical members are supported loosely.

JOSEPH "W 

